Worn out striking pierced tip of tongue (8)
I believe the answer is:
decrepit
'worn out' is the definition.
(I've seen this before)
'striking pierced tip of tongue' is the wordplay.
'striking' is an anagram indicator ('strike' can mean 'hit' or 'disrupt').
'tip of' indicates taking the first letters.
The first letter of 'tongue' is 't'.
'pierced' is an anagram of 'decrepi'.
'decrepi'+'t'='DECREPIT'
(Other definitions for decrepit that I've seen before include "In the last stages of decay" , "Run-down by old age or hard use" , "ruined by neglect" , "Getting on" , "run down" .)